Biochemical and Biophysical Research Communications, Vol.508, No.3, 965-972, 2019
Autophagy in FOXD1 stroma-derived cells regulates renal fibrosis through TGF-beta and NLRP3 inflammasome pathway
Renal fibrosis is the final common pathway of various renal injuries and it leads to chronic kidney disease. Recent studies reported that FOXD1-lineage pericyte plays a critical role in tubulointerstitial fibrosis (TIF). However the regulatory mechanisms remain unclear. Autophagy is a cellular process of degradation of damaged cytoplasmic components that regulates cell death and proliferation. To investigate the role of autophagy in FOXD1-lineage pericytes on renal TIF, we generated the FOXD1-lineage stromal cell-specific Atg7 deletion (Atg7(Delta FOXD1)) mice. FOXD1-lineage stromal cell-specific Atg7 deletion enhanced renal TIF through Smad-dependent transforming growth factor (TGF)-beta signaling after unilateral ureteral obstruction (UUO). FOXD1-lineage stromal cell-specific Atg7 deletion increased the accumulation of interstitial myofibroblasts and enhanced the differentiation of pericytes into myofibroblasts after UUO. Peritubular capillary rarefaction was accelerated in Atg7(Delta FOXD1) mice after UUO. Atg7(Delta FOXD1) mice increased the accumulation of SQSTM1/p62-positive aggregates in the obstructed kidney and resulted in increased expression of NLRP3 inflammasome, interleukin (IL) 1-beta and caspase-1 signaling pathway, which enhanced apoptosis of interstitial cells after UUO. In summary, our data showed that autophagy in FOXD1-lineage stromal cells plays a protective role in renal TIF through regulating the Smad4 dependent TGF-beta an NLRP3 infiammasome signaling pathway. (C) 2018 Elsevier Inc. All rights reserved.